1. Field of the Invention
The present invention is a process for the transformation of a known steroidal acetonide (I) intermediate to rofleponide (II). Rofleponide (II) is known to be useful as a pharmaceutical agent.
2. Description of the Related Art
U.S. Pat. No. 5,939,409 discloses rofleponide (II) and its use as a glucocorticosteroid useful in treating inflammatory, allergic or immunologic diseases of the respiratory airways (asthma, rhinitis), in skin (eczema, psoriasis) or bowel (ulcerative colitis, Morbus Crohn).
U.S. Pat. No. 5,939,409 discloses the acetonide (I) to be a useful intermediate in the production of rofleponide.
U.S. Pat. No. 5,939,409 discloses a transacetalization process of the acetonide (I) to rofleponide (II). The transacetalization process of U.S. Pat. No. 5,939,409 produces rofleponide (II), but requires the use of small grains of an inert material to prevent a big sticky lump from forming, see column 4, lines 1-9. The process of the present invention does not require the use of an inert material.
European Patent Application 0 262 108 discloses the transacetalization of acetonide (I) to rofleponide (II) but requires the use of small grains of an inert material. The process of the present invention does not require the use of an inert material.